Compositions comprising a graphene-based material as lubricant additives

Abstract

Nanoparticle compositions contain a graphene-based material. A preparation process involves providing several components and milling a mixture. The nanoparticle compositions can be used as a lubricant additive to improve tribological performance, in particular to improve anti-friction and anti-wear performance on metal parts. A corresponding lubricant composition contains these nanoparticle compositions.

1 : A nanoparticle composition, comprising:
 one or more graphene nanoparticle (A),   one or more polymer (B),   one or more silane compound (C), and   one or more base fluid (D),
 wherein the one or more graphene nanoparticle (A) is a multilayered graphene-based material containing oxygen groups, with a surface area BET between 200 n/g and 1,500 m 2 /g, and G/D ratio between 0.5 and 2 in accordance with ISO/TS 80004-13, 
 wherein the one or more polymer (B) is obtainable by polymerizing a monomer composition comprising: 
 a) 1 to 30% by weight, based on a total weight of the monomer composition, of one or more functional monomer selected from the group consisting of:
 a1) aminoalkyl (meth)acrylates and aminoalkyl (meth)acrylamides; 
 a2) nitriles of alkyl (meth)acrylic acid and other nitrogen-containing alkyl (meth)acrylates; 
 a3) (meth)acrylates of ether alcohols; 
 a4) oxiranyl alkyl (meth)acrylate; 
 a5) phosphorus-, boron-A and/or silicon-containing alkyl (meth)acrylates; 
 a6) heterocyclic alkyl (meth)acrylates; 
 a7) vinyl halides; 
 a8) vinyl esters; 
 a9) vinyl monomers containing aromatic groups; 
 a10) heterocyclic vinyl compounds; 
 a11) vinyl and isoprenyl ethers; and 
 a12) methacrylic acid and acrylic acid, 
 
 b) 30 to 70% by weight of one or more alkyl (meth)acrylate monomer, wherein each alkyl group of the one or more alkyl (meth)acrylate monomer is independently linear, cyclic, or branched and comprises from 1 to 40 carbon atoms, based on the total weight of the monomer composition, and 
 c) 20 to 60% by weight of one or more polybutadiene-based macromonomer having a number-average molecular weight (M n ) of 500 to 10,000 g/mol, based on the total weight of the monomer composition, 
   wherein the nanoparticle composition comprises 0.02 to 5% by weight, based on a total weight of the nanoparticle composition, of the one or more silane compound (C) of formula (IV)
   Si(R)(M) h (X) 3-h   (IV),
 
 wherein 
 0≤h≤2; 
 M is a branched or linear C 1  to C 4  alkyl residue, 
 R is a branched or linear, aliphatic, aromatic, or mixed aliphatic-aromatic C 1  to C 30  carbon-based group, or R is a branched or linear, aliphatic, aromatic, or mixed aliphatic-aromatic C 1  to C 30  carbon-based group with a functional group selected from the group consisting of carboxy, carbonyl, hydroperoxycarbonyl, cyan, formyl, oxo, thioxo, hydroxy, amino, imino, hydrazino, and epoxy; 
 X is selected from the group consisting of H, Cl, and a group OY, 
 wherein Y is H or a C 1  to C 8  branched or linear alkyl-, alkenyl-, aryl-, or aralkyl-group, branched or linear C 2  to C 8  alkylether-group, or a mixture thereof; 
   and   wherein the nanoparticle composition is obtainable by milling.   
     
     
         2 : The nanoparticle composition according to  claim 1 , wherein the one or more polybutadiene-based macromonomer c) has a number-average molecular weight (M n ) of 1,500 to 7,500 g/mol. 
     
     
         3 : The nanoparticle composition according to  claim 1 , wherein the one or more polymer (B) has a weight-average molecular weight (Mw) of 10,000 to 1,000,000 g/mol. 
     
     
         4 : The nanoparticle composition according to  claim 1 , wherein the one or more polymer (B) is obtainable by polymerizing a monomer composition comprising:
 a) 1 to 30% by weight of the one or more functional monomer, as component a), based on the total weight of the monomer composition; and   b1) 30 to 60% by weight of one or more alkyl (meth)acrylate of formula (I), as a first component b):   
       
         
           
           
               
               
           
         
         wherein R is hydrogen or methyl, R 1  means a linear, branched, or cyclic alkyl residue with 1 to 8 carbon atoms, based on the total weight of the monomer composition; and 
         b2) 0 to 20% by weight of one or more alkyl (meth)acrylate of formula (II), as a second component b): 
       
       
         
           
           
               
               
           
         
         wherein R is hydrogen or methyl, R 2  means a linear, branched, or cyclic alkyl residue with 9 to 15 carbon atoms, based on the total weight of the monomer composition; and 
         b3) 0 to 20% by weight of one or more alkyl (meth)acrylate of formula (III), as a third component b): 
       
       
         
           
           
               
               
           
         
         wherein R is hydrogen or methyl, R 3  means a linear, branched, or cyclic alkyl residue with 16 to 40 carbon atoms, based on the total weight of the monomer composition; and 
         c) 20 to 60% by weight of the one or more polybutadiene-based macromonomer having a number-average molecular weight (M n ) of 500 to 10,000 g/mol, as component c), based on the total weight of the monomer composition. 
       
     
     
         5 : The nanoparticle composition according to  claim 4 , wherein the one or more polymer compound (B) is obtainable by polymerizing a monomer composition comprising:
 a1) 0.5 to 5% by weight of an aminoalkyl, as a first component a), based on the total weight of the monomer composition;   a9) 5 to 15% by weight of a vinyl monomer containing aromatic groups, as a second component a), based on the total weight of the monomer composition;   b1) 35 to 50% by weight of the alkyl (meth)acrylate monomer of formula (1), as the first component b), based on the total weight of the monomer composition;   b2) 1 to 10% by weight of the alkyl (meth)acrylate monomer of formula (II), as the second component b), based on the total weight of the monomer composition;   c) 30 to 50% by weight of the one or more polybutadiene-based macromonomer having a number-average molecular weight (M n ) of 500 to 10,000 g/mol, as the component c), based on the total weight of the monomer composition.   
     
     
         6 : The nanoparticle composition according to  claim 1 , wherein the weight contents of monomers a), b), and c) of the monomer composition sum up to 100% by weight, based on the total weight of the monomer composition. 
     
     
         7 : The nanoparticle composition according to  claim 1 , wherein the one or more silane compound (C) of formula (IV) is octyltrimethoxysilane, hexadecyltrimethoxysilane, 3-aminopropyltriethoxysilane or 3-glycidyloxypropyltriethoxysilane. 
     
     
         8 : The nanoparticle composition according to  claim 1 , wherein the nanoparticle composition comprises:
 1 to 20% by weight of the or more graphene nanoparticle (A),   0.5 to 30% by weight of the one or more polymer (B),   0.02 to 5% by weight of the one or more silane compound (C),   45 to 98.48% by weight of the one or more base fluid (D),   based on the total weight of the nanoparticle composition.   
     
     
         9 : The nanoparticle composition according to  claim 8 , wherein components A), B), C, and D) sim up to 100% by weight, based on the total weight of the nanoparticle composition. 
     
     
         10 : A process for preparing the nanoparticle composition as defined in  claim 1 , the process comprising:
 (i) providing the one or more graphene nanoparticle (A);   (ii) providing the one or more polymer (B);   (iii) providing the one or more silane compound (C);   (iv) providing the one or more base fluid (D);   (v) combining components (A) to (D) to obtain a mixture; and   (vi) milling the mixture of (v).   
     
     
         11 : The process according to  claim 10 , wherein in (v) components (A) and (C) are first mixed together by spraying or ball milling and then mixed with components (B) and (D). 
     
     
         12 : A lubricating oil composition, comprising:
 the nanoparticle composition as defined in  claim 1 , and   one or more base oil (E).   
     
     
         13 : The lubricating oil composition according to  claim 12 , wherein the lubricating oil composition further comprises one or more additive component (F) selected from the group consisting of an antioxidant, an anti-wear additive, a pour point depressant, a corrosion inhibitor, a metal passivator, an electrostatic discharge depressant, a defoaming agent, a seal fix, a seal compatibility agent, and a mixture thereof. 
     
     
         14 . The lubricating oil composition according to  claim 13 , wherein the lubricating oil composition comprises,
 50 to 9999% by weight of the one or more base oil (E),   0.01 to 50% by weight of the nanoparticle composition, and   0 to 20% by weight of the one or more additive component (F),   based on a total weight of the lubricating oil composition.   
     
     
         15 : A method for preparing a lubricating oil composition, the method comprising:
 combining the nanoparticle composition as defined in  claim 1  with one or more base oil.   
     
     
         16 : The nanoparticle composition according to  claim 1 , wherein in the formula (IV), R is selected from the group consisting of a linear aliphatic C 8  carbon-based group, a linear aliphatic C 16  carbon-based group, a linear aliphatic 3-aminopropyl group, and a 3-glycidyloxypropyl group, and/or
 X is methoxy or ethoxy.   
     
     
         17 : The nanoparticle composition according to  claim 3 , wherein the one or more polymer (B) has a weight-average molecular weight (Mw) of 150,000 to 350,000 g/mol. 
     
     
         18 : The nanoparticle composition according to  claim 4 , wherein the monomer composition comprises:
 10 to 20% by weight of the component a),   35 to 50% y w % eight of the first component b),   1 to 10% by weight of the second component b),   0 to 10% by weight of the third component b), and   30 to 50% by weight of the component c),   based on the total weight of the monomer composition.   
     
     
         19 : The nanoparticle composition according to  claim 5 , wherein in the monomer composition:
 the first component a) is N-(3-dimethyl-aminopropyl)methacrylamide,   the second component a) is styrene,   the first component b) is methyl methacrylate and/or butyl methacrylate,   the second component b) is lauryl methacrylate, and   the component c) is a macromonomer derived from a reaction of an ester of a (meth)acrylic acid and a hydroxylated hydrogenated polybutadiene having a number-average molecular weight (Mu) of 1,500 to 5,500 g/mol.   
     
     
         20 : The method according to  claim 15 , wherein the lubricating oil composition is a gear oil composition, a transmission oil composition, a hydraulic oil composition, an engine oil composition, a marine oil composition, an industrial lubricating oil composition, or grease.